Phase I development of the Knee Height Measuring Device (KHMD) produced a prototype instrument capable of assessing linear growth changes with an accuracy of 0.5mm within a time period of one month or less. Field testing during Phase I has demonstrated the potential value of research applications, including the much-needed study of short term growth patterns. Phase II efforts will include design refinements aimed at improving measurement error, measurement to remove, those sources of measurement variability which are not associated with linear growth. Phase II plans also include the further standardization of KHMD methodology, the establishment of reference norms, and clarification of the relationship between growth in the lower limb and other physical measures of growth. During Phase II the pre-production prototype will be further evaluated in a variety of clinical settings, for the purpose of identifying those refinements most desirable to incorporate into Phase III production plans.